Calculating machine



Jan. 22, 1929.

1,700,057 w. s. JOHNSON CALCULATING MACHI NE Original Filed April 23.1921 Patented Jan. 22, 1929.

UNITED STATES 1,700,057 PATENT OFFICE.

WALTER S. JOHNSON, OF PROVIDENCE, RHODE ISLAND.

CALCULATING MACHINE.

Application filed April 28, 1921, Serial No. 463,871. Renewed .Tune 21,1828.

This invention relates to calculating machines.

In calculatin machines of the general type illustrated in the patent toGeorge C. Chase No. 1,329,262, dated January 27, 1920, the computingoperation is performedby a series of computing wheels arranged to beactuated upon depression of a series of operating keys. The actuatingmechanism as well as the key, is returned to an initial position byreturn springs after each computing operation. In performing thecomputingoperation the operator is required to exert sufiicient pressureupon the key not only to overcome the frictional resistance offered bythe actuating mechanism and computing wheels, but also sufiicientadditional pressure to overcome the return springs, with the result thatbecause I of the stiffness required of the springs as heretoforeemployed, the calculating machines all had relative hard key movement.

The object of the present invention is to provide a calculating machinehaving an easier and more desirable key movement.

In the drawing illustrating the preferred embodiment of the inventionFig. 1 is an elevation of the right-hand side of the calculatingmachine; Figs. 2 and 3 are end and side elevations respectively of themechanism for actuating one of the computing wheels; and Fig. 4 is aside elevation showing the actuating mechanism in a different positionof operation.

The mechanism of each section of the calculating machine illustrated inthe drawing for performing the computing operation includes a series ofkeys 10, a number wheel 12, and connections between the keys and numberwheel whereby depression of one of the keys causes rotation of thenumber wheel. The connections between the keys and number wheel includea slide bar 14 having a rack 16 engaging teeth upon a cam member 18. Thenumber wheel 12 is provided with a pinion 13 into engagement with whichan actuating segment 22 is adapted to be moved so as to thereafter causerotation of the pinion and number wheel as the actuating segment ismoved. The actuating segment 22 is pivoted upon an oscillatory bellcrank 24 pivoted at 24, one arm 26 of the bell crank being provided witha cam roll 28 adapted to be lifted during the first part of the keydepression by a cam 30 pivoted upon the cam member 18. A second slidebar 17 is arranged beneath the slide bar 14 and upon movement toward thefront of the machine operates to throw a locking pawl 19 plvoted at 19into engagement with the teeth of a ratchet 21 upon the lower portion ofthe actuating segment 22 in order to prevent over-rotation or spinningof the number wheel 12. The slide bars 14 and 17 together with the keys10 are returned to an initial position after a key depression byreturning springs 23, 25 cooperating with the racks. The actuatingsegment 22 is returned to an initial position by a return spring 27. Theparts thus far described, with the exception of the cam 30, are of thesame general construction and have the same mode of operation as thecorresponding parts in the calculating machine of the above mentionedChase patent.

At the end of the key depression the actuating segment 22 and associatedparts occupy the position illustrated in Fig. 3, in which the actuatingsegment 22 is in engagement with the pinion 13 upon the number wheel 12,being held in such position by the pivoted cam 30, the lower surface ofwhich rides upon a cam roll 40 upon the upper end of an arm 42 of a bellcrank 44 pivoted upon the frameat 45. The bell crank 44 is held, duringthe depression of the key 10, in a stationary position to support thecam 30 in its movement by a spring latch 46 in engagement with the tipof the second arm 48 of the bell crank.

In order to decrease the frictional resistance offered to the returnsprings 23, 25 and 27 so that return springs of lighter construction maybe used for the purpose of diminishing the power required to be exertedby the operator to depress the key 10 during the computing operation,provision is made for permitting the actuating segment 22 to becomedisengaged from the pinion 13 at the start of the return movement of thekey 10 after a depression thereof, to thereby permit the actuatingsegment 22 to be more easily returned to an initial or starting positionby the spring 27. In this manner the release of the actuating segment 22at the beginning instead of at the end of the return stroke of theoperating key 10 gives a greater length of time within which the returnspring 27 may act, so that a correspondingly lighter spring may be used.For this purpose the latch 46 which has held the bell crank 44stationary during the key depression, is lifted from engagement with thetip of the second arm 48 of the bell crank. This is accomplished at thebeginning of the return movement of the key by the engagement of a dog50 upon the end of an oscillatory pawl 52 with a finger 54 upon thelower portion of the latch. The pawl 52 and dog are swung tothe right,viewing Fig. 3, by movement of the second or lower rack bar 17 under theinfluence of the spring 25 at the beginning of the return or upwardmovement of a key 10 after a depression thereof. The release of the bellcrank 44 operates to permit the actuating segment 22 to becomedisengaged from the pinion 13, and immediately thereafter the cam member18, cam roll 40, cam 30 and actuating segment 22-are moved from theposition illustrated in Fig. 3 to that shown in Fig. 4 by the returnspring 27 It will therefore be apparent that the frictional resistanceof present constructions offered by the segment 22 as it engages thepinion 13 is eliminated and a lighter spring 27 may be used. Thedecrease in the frictional resistance enables springs of lighterconstruction to be used throughout so that a calculating machineembodying the present invention has a much easier key movement thanprior constructions of such machines.

After the latch 46 has been lifted and the bell crank 44 released, theactuating segment 22 immediately drops, returning to its initialposition. During the remaining portion of the return movement of thekey, the rack bar 17 and the pawl 52 remain practically stationary inthe position illustrated in Fig. 4 and the pawl 52 is reset by movementto the left upon movement of the rack bar 17 to the left upon the nextkey depression. A. coil spring enables the dog 50 to turn sufficientlyduring the resetting operation to permit the tip of the finger 54 toride over the end thereof.

During the latter art of the return movement of the key, the ell crank44 is returned to an operative position such as is illustrated in Figs.1 and 3, in which the tip of the second arm 48 thereof is engaged by thelatch 46 and in which the cam roll 40 is in position to cause the cam 30to be lifted upon the next key depression. For this purpose the cammember 18 is provided with a small cam projecting therefrom which isadapted to engage the cam roll 40 to oscillate the bell crank 44 to theleft thus positioning the parts, as shown in Fig. 1, in readiness forthe next key depression. Then as the next key is depressed the actuatingsegment 22 is forced into engagement with the pinion 13 through theaction of the cam 30 and the actuating segment is thereafter'rotated toperform the computing operation.

Having thus described the invention what is claimed is 1. A calculatingmachine having, in combination, a computing wheel, a series of keys, anactuating segment, connections permitting movement of the actuatingsegment into engagement with the computing mechanism upon depression ofone of the keys, support ing means for maintaining said connections inposition to hold the segment in engagement with the computing mechanismduring depression of the key, means for releasing the supporting meansat the beginning of the return movement of the key to disengage thesegment from the computing mechanism, and means for effecting asimultaneous independent return of the key and the segment.

2. A calculating machine having, in combination, a computing wheel, aseries of keys,

an actuating segment, connections permitting movement of the actuatingsegment into engagement with the computing mechanism upon depression ofone of the keys, supporting means for maintaining said connections inposition to hold the segment in engagement with the computing mechanismduring depression of the key, means for releasing the supporting meansat the beginning of'the return movement of the key to disengage thesegment from the computing mechanism, and means for restoring thesupportin means to operative position upon return oi the parts to theiroriginal positions.

3. A calculating machine having, in combination, a computing wheel, aseries of keys, actuating means for the computing wheel, connectionsbetween the'keys and the actuating means for moving the latter intoengagement with the computing wheel upon depression of a key, meanspermitting disengagement of the actuating means from the computing Wheeland from said connections at the beginning of the return movement of thekey, and return springs for simultaneously and independently returningthe actuating means and the key after dlsengagement of the former fromthe computing wheel.

4. A calculating machine having, in combination, a computing wheel,means for actuating the computing wheel including a series of keys, apinion connected to the computing wheel, an actuating segment, a memberadapted to be moved upon depression of the key, a cam pivoted upon saidmember, means cooperating with said cam for causing the actuatingsegment to engage the pinion and to rotate it, and means for releasingsaid cam to permit the segment to be disengaged from the pinion at thebeginning of the return movement of the key.

5. A calculating machine having, in combination, a computing wheel, aseries of keys, a pinion connected to the computing wheel, an actuatingsegment, a cam member adapted to be moved upon depression of the key, acam pivoted upon the cam member for raismg the actuating segment intoengagement with the pinion, a lever for normally holding the cam inposition to engage the actuating segment, and means operated upon thebeginning of the return movement of the key for releasing the lever toallow the actuating segment to drop out of engagement with the pinion.

6. A calculating machine having, in combination, a computing Wheel, aseries of keys, a pinion connected to the computing Wheel, an actuatingsegment, a cam member adapted to be moved upon depression of the key, acam pivoted upon the cam member for raising the actuating segment intoengagement with the pinion, a bell crank lever having an end engagingthe under side of the cam, a latch engaging the bell crank lever in amanner to hold the cam normally in position to engage the actuatingsegment, and a slide operated by the keys and adapted to move therelease latch and allow the actuating segment to drop out of engagementwith the pinion upon the beginning of the return movement of the i Acalculating machine having, in combination, computing mechanism, aseries of keys, actuating means for the computing mechanism, means formoving the actuating means into engagement with the computing mechanismupon depression of a key, means including a latch for maintaining theactuating'means in engagement with the computing mechanism duringdepression of the key, means for tripping the latch to disengage theactuating means'from the computing Wheel at the beginning of the returnmovement of the key, and independent means for simultaneously returningthe actuating means and the key after disengagement of the former fromthe computing mechanism.

8. A calculating machine having, in combination, computing mechanism, aseries of keys, actuating means for the computing mechanism, means formoving the actuating means into engagement with the computing mechanismupon depression of a key, means including a latch for maintaining theactuating means in engagement with the computing mechanism duringdepression of the key, means for tripping thelatch to disengage theactuating means from the computing wheel at the beginning of the returnmovement of the key, independent means forsimultaneously returning theactuating means and the key after disengagement of the former from thecomputing mechanism, and means for resetting the latch at the end of thereturn movement.

WALTER S. JOHNSON.

